Double-hung windows are commonly used in residential and other structures. Double-hung window assemblies typically include a window frame and a pair of window sashes. The bottom sash may be positioned inwardly of the top sash so that the sashes overlap and can be slid vertically relative to one another along the guide rails of the window frame. Window sashes can be made of wood, extruded plastic frame members or metal frame members joined at the corners, for example, to form a generally rectangular frame in which the glazing is installed.
Double-hung windows often include a locking mechanism located at or near the point where the sashes meet when the window assembly is in a closed position. A locking mechanism may be fixed on the top rail of the bottom sash and the corresponding latch-receiving mechanism is fixed on the bottom rail of the top sash. When the window sashes are in the closed position, the lock may be secured to prevent movement of the sashes.
Many double-hung windows also include latches (including, for example, tilt or vent latches) that are typically mounted on the opposing ends of the top rail of the bottom sash. The tilt latches generally are manually activated to selectively engage portions of the window frame, for example, grooves formed therein. When in an extended position, the tilt latches engage the window frame, thereby preventing the bottom sash from pivoting relative to the window frame, yet allowing the bottom sash to be slid relative to the frame in a vertical direction. In a retracted position, the tilt latches allow the bottom sash to be pivoted outwardly from the frame, thus allowing easy access to the outer surface of the panel housed within the bottom sash. Tilt latches can also be incorporated into the top sash to allow similar pivoting motion relative to the window frame.